導賞點 3
為何建了水泥級,山徑仍是這麼爛?
Why the trails are so eroded even though concert steps were built?
離開水泥路,踏上麥理浩徑的天然泥路段,你會發現這裡本身的泥土結構十分鬆散,政府部門在沖刷嚴重的段落曾用不同的方法改變路況,在這段短短的山徑中,有水泥石級,有的加了碎石,有的使用膠網,有的是水泥板……等不同的修建方法。
Leaving the cement road, you will find that the soil structure of Maclehose Trail is very loose. The government has used different methods to change road conditions in heavily scoured sections. In this short trail, there are different construction methods, such as cement grade, some added gravel, some use plastic mesh, some cement plate and so on.
可是修建的水泥石級似乎制止不了水土流失,不少修建部分己損壞,旁邊也總是有條深深的沖溝,使水泥級看上去有點欠穩。為什麼?
But the cement grade didn’t seem to stop the erosion. Many of the buildings were partially damaged, and there was always a deep gully next to them, making the cement grade look a little unstable. Why were that happened?
原來大欖郊野公園曾經是提供填海工程泥土的採泥區,加上這山頭屬於花崗岩,容易風化,可以說這裡天生就是一副容易發生水土流失的體質。
The reason was that Tai Lam Country Park used to be a dredging area for reclamation works. In addition, this hill is made of granite, which is easy to be weathered. Therefore, it is naturally prone to soil erosion.
建石級,無疑可即時讓行山人士「有路可走」,但如沒同時改善去水的問題,水只會越過堅硬的水泥或石頭面,集中在兩旁向下傾瀉,匯聚更大的衝力、更容易沖散兩旁的泥土。
The stone grade will undoubtedly give visitors a way to go. But without the improvement of the water removal problem, the water will only pass over the hard cement or stone surface and pour down on both sides, gathering more momentum and dispersing the soil on both sides more easily.
所以,維修山徑工作中,「水的管理」非常重要,要改善路段整體的去水系統,才是治本。
Therefore, “water management” is very important in the maintenance of the mountain trail. To improve the overall water removal system of the road section is the root cause.